西瓜枯萎病药剂筛选及其防效研究

Study on Screening of Fungicide and Control Effect of Fusarium Wilt in Watermelon

采用菌丝生长速率法测定了10种杀菌剂对尖孢镰刀菌西瓜专化型的抑制作用,从中筛选出了4种抑菌效果好的药剂进行了室内毒力测定和温室盆栽生物测定。结果表明:80%多菌灵2 000倍、25%戊唑醇4 000倍、40%氟硅唑3 000倍、25%丙环唑2 000倍、12.5%烯唑醇4 000倍的抑菌效果达到90%以上。烯唑醇对菌丝生长的抑制作用最强,EC50值为0.1901mg/L,其次是戊唑醇和多菌灵,EC50值分别为1.8723mg/L和1.8847mg/L;温室盆栽试验结果表明,播前灌施烯唑醇和多菌灵对西瓜枯萎病的防治效果最好,36d时的防效分别为89.52%和72.07%。然而烯唑醇明显抑制西瓜幼苗的正常生长。可见,播前拌土施用多菌灵对西瓜枯萎病有理想的防治效果,可优先用于西瓜枯萎病的防治。

The inhibition activities of 10 chemical fungicides against Fusarium oxysporium f.sp.niveum were determined by the mycelial growth rate test.Control efficacies of the 4 promising fungicides were carried out under greenhouse condition.The results showed that inhibition effects of 5 fungicides including the 80% carbendazim 2 000×,25% tebuconazole 4 000×,40% flusilazole 3 000×,25% propiconazole 2 000×,12.5% diniconazole 4 000× were above 90%.The inhibition activity of diniconazole against mycelial growth of the pathogen was strongest,which EC50 was 0.1901 mg/L,then the next were tebuconazole（EC50 1.8723 mg/L） and carbendazim（EC50 1.8847 mg/L）.The control efficacies of carbendazim and diniconazole to watermelon Fusarium wilt were 72.07% and 89.52% in the pot experiments in greenhouse,respectively.However,it found that diniconazole significantly inhibited the growth of watermelon seedling.In conclusion,carbendazim was recommended to be used for controlling watermelon Fusarium wilt in commercial fieldapplying into soil.